Axial Compression Properties of Recycled Concrete-Filled Circular Steel Tubular Column Subject to Corrosion.

In order to investigate the change in the axial compression performance of circular recycled concrete-filled steel tubular short columns under chloride ion corrosion, 24 circular recycled concrete-filled steel tubular (RCFST) short columns and 12 circular natural concrete-filled steel tubular (NCFST) short columns for axial compression tests after being subjected to different corrosion degrees were designed. The experimental parameters include the corrosion degree (0, 2, 4, 6, 8, 10, 12, 14%) and the recycled concrete replacement rate (0, 100%). The experimental results show that the damage mode of the specimen after corrosion is localized buckling deformation of the steel tube. Due to the good confinement effect of the steel tube, the internal concrete was crushed only at the localized buckling part of the steel tube. The stiffness and ductility decreased significantly with increasing corrosion degree. As the corrosion degree increased from 0 to 14%, the stiffness of the circular RCFST short columns decreased by approximately 36.3%, and the ductility dropped by around 23.3%. And the corrosion resistance of the circular RCFST short column was worse than that of the circular NCFST short column. Based on the experimental results, the ultimate load capacity calculation model of the circular concrete-filled steel tubular short column is proposed.